Since the advent of the resist for KrF excimer laser (248 nm), an image-forming method utilizing chemical amplification has been used as the image-forming method of a resist so as to compensate for sensitivity reduction due to light absorption. To explain the image-forming method by taking a positive chemical amplification image-forming method as an example, an acid generator in the exposed area decomposes by exposure to generate an acid, an alkali-insoluble group is changed to an alkali-soluble group by utilizing the generated acid as a reaction catalyst in baking after exposure (PEB: Post Exposure Bake), and the exposed area is removed by alkali development. The positive image forming method utilizing chemical amplification mechanism has been now the main stream of image forming method.
Further, for the purpose of increasing resolution by shortening of wavelength, what is called an immersion method of filling the space between the projection lens and the sample with a liquid of high refractive index is known (hereinafter also referred to as “an immersion liquid”). For instance, examples of reducing development defects and reforming surface contact angle and the like by using a specific resin having a fluorinated alkyl group in a positive resist composition are disclosed in Published U.S. Patent Application 2011/0255061, JP-A-2008-88343 (The term “JP-A” as used herein refers to an “unexamined published Japanese patent application”.) and JP-A-2011-132273.
However, in the above positive image-forming method, an isolated line or a dot pattern can be successfully formed, but when an isolated space or a fine hole pattern is formed, the profile of the pattern is liable to be deteriorated.
Accordingly, to cope with the demand for further fining of a pattern, not only a positive resist film of now in the main stream but also the technique of resolving a negative pattern of a resist film obtained from a chemical amplification resist composition with an organic developer is also known in recent years. As such technique, for example, in a negative pattern forming method of performing immersion exposure and using an organic developer as the developer, technique of adding a resin containing a repeating unit having a specific alkyl chain in addition to the main resin is known (for example, refer to Published U.S. Patent Application 2011/0294069).